anv: fix use of comma operator

This doesn't fix any bug at the moment because the next statement is
'true' which happens to be APIMODE_D3D, but if that changes it could.

The fixes tags is as far I could go but the error predates it (2016 is
probably far enough).

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: 8db6f2e6 ("anv/pipeline: Roll genX_pipeline_util.h into genX_pipeline.c")
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
(cherry picked from commit 772a5f98)
[Juan A. Suarez: resolve trivial conflicts]
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>

Conflicts:
	src/intel/vulkan/genX_pipeline.c